Polymers of carbon monoxide and ethylenically unsaturated hydrocarbons have been known for some time. Brubaker, U.S. Pat. No. 2,495,286, produced polymers of relatively low carbon monoxide content by reaction of ethylene and carbon monoxide in the presence of free radical catalysts. U.K. Patent No. 1,081,304 disclosed the production of polymers in the presence of alky-phosphine complexes of palladium. Nozaki extended the scope of this reaction to include aryl phosphine complexes of palladium, U.S. Pat. No. 3,689,460, to include tetrakis(triarylphosphine) complexes of palladium, U.S. Pat. No. 3,694,412 and to acidic cyanide complexes of palladium, U.S. Pat. No. 3,835,123.
More recently, a class of linear alternating polymers has been produced in good yield and the polymers have attracted greater interest. Production of this class of polymers, known as polyketones, is illustrated by published European patent application 121,965 which describes reaction of carbon monoxide with ethylenically unsaturated hydrocarbon(s) in the presence of compounds of certain Group VIII metals, anions of nonhydrohalogenic acids of pKa less than about 2 and bidentate ligands of phosphorus. In copending U.S. application Ser. No. 940,876 filed Dec. 10, 1986, it is disclosed that certain oxidizing agents improve the performance of polyketone polymerization catalysts formed from compounds of the Group VIII metals, anions of non-hydrohalogenic acids of pKa less than about 6 and bidentate nitrogen ligands including organic nitro and nitrite compounds as well as others such as quinones. While it is known that quinones may also improve the performance of polyketone polymerization catalysts which incorporate bidentate phosphorus ligands, e.g., copending U.S. patent application Ser. No. 021,946, filed Mar. 5, 1987, it would be of advantage to extend the promotional effects of organic nitro and nitrite compounds to catalytic systems containing bidentate phosphorus ligands.